Where do you zero

[Tom R]

Where do you all zero your trodes from top or bottom? If you do zero from bottom how does the set up sheet work for tool lengths. We currently set zero up from the top of the trode and the set up sheet tells us the proper tool lengths. Dose anybody have pros and cons of ether way?

[Lee.]

For me it all depends where I am likely to want to reference from during the machining process.

 

I am routering, so I prefer table as zero.

[Thee Dragracer1951]

I'm most likely not doing what you are doing. But I Zero from the table. Put the top of the part in the G54.

[Kannon]

I do electrodes with the top ALWAYS zero. I very seldom have to mess with the clearance/retract tab cause its above zero. I would hate to have it set to .2 and have it drive it down into the electrode.

[edmBosto]

I am 100% agreeing with Kannon on this.

I make electrodes and the top is always Z 0.0

[Thee Rickster ™]

I mount everything to a plate that locates and

mounts to the table. dowel and mounting pattern

On backsides

 

Never Have to dial or pick up origin because

the plate locates and centre of travel is X0,Y0

 

Mold bases,slides and inserts.

 

I program inserts off the bot(top of plate)

Slide off top of block.

Mold bases, P/L is Z-0-(Usually top is zero)

unless the p/l is machined down.

[mold100]

everything off the table, and use z offset, then I never have to pick a tool length up except the first time I put it in, also because most of my stuff has no flat area on the top so if i break a tool I would be screwed for a z pick up.

[Programinator]

off the table here better that way when going from setup to setup

[Reece L Gibson]

Plate work,X0Y0, center of the plate, Z0, top of stock

Vise work, X0Y0,upper left hand corner,Z0 top of stock

Round work,X0Y0, center line,Z0 top of stock

 

Fixture work, locator pin some where on the fixture, Z0, a datum ref point

 

Castings, datum A, then datum B, then datum C(asumming a fixture)

 

Usually you have to adapt the the way the company has been doing it for a while

[Guest CNC Apps Guy 1]

Everytihg from the bottom of part/stock ALWAYS! Material/Stock varies too much so now that's a non-issue. The bottom NEVER changes. Since I always do it this way, retracts are never a problem.

 

As far as tool lengths - ALWAYS WITHOUT EXCEPTION I use positive tool offsets. My fixture offset controls place in space X, Y, Z, and whatever rotary positions I need to set.

 

HTH

[Tom R]

Thanks for all your info! CNC Apps Guy how do your positive tool offsets work I've tried to program Z zero at the bottom and can't figure out how you get your tool lengths on the setup sheet besides manual wighting them all out! Is there a way with WCS to manipulate the set up sheet?

[Guest CNC Apps Guy 1]

I don't know if there is a way. The other thing about positive tool lengths is that you can actually capture the data from the tool definition. I have a post somewhere that calculates that value for you. It gets it cvlose enough to the real number that when you touch off your tools with the laser or plunger you'ew within .010 if your setup guy obeyed the setup sheet.

 

As far as the WCS tying into the Setup Sheet... I've never done that so I don;t know.

[Fred @ Slate Industries]

50 / 50 If the top is Z 0 then I don't have to

do any explaining on burn depths.

If the shape is so erratic (and know one would have a clue where it was in relation to anything)

I come off the bottom.

Once (Crack of dawn on a monday) I couldnt work from the top so I switched too

the bottom, loaded it and Forgot to offset my tools from Z bottom

Dude, I saw "Fire Under Water" !!!

Luckily there was a massive angle on the part so

the tool Wedged the workpiece off side ways

through the vice jaws.

That Mangled Collet Nut sits right here in front of me